Methods of and apparatus for coiling strand material

ABSTRACT

A strand coiler is provided with individually mounted pins spaced about a strand-engagement surface of a drum-type capstan. Each of the pins is mounted rotatably and reciprocally and is urged inwardly axially toward the strand-engagement surface by an associated compression spring. The pins provide the necessary force between the strand material and the engagement surface of the coiler so that the coiler functions satisfactorily and problems of adjustment and wear experienced with priorly used devices are significantly reduced.

United States Patent Monell Apr. 2, 1974 154] METHODS OF AND APPARATUS FOR OTHER PUBLICATIONS COlLlNG STRAND MATERIAL Haugwltz, German Printed Publication, Appt. No. [75] Inventor: Bradner Neil Monell, Litchfield 1 139 711 published 15 19 2 Park, Ariz. v [73] Assignee: Western Electric Company, Inc., Primary ExaminerBmy Taylor New York, Attorney, Agent, or Firm-E. W. Somers; R. P. Miller;

. Don P. Bush [22] Filed: Oct. 23, 1970 Appl. No.: 83,279

[52] [1.8. CI. 242/83, 140/921 [51] Int. Cl. B2lc 47/14 [58] Field of Search 242/82, 83, 47.13, 47.12, 242/147 R; 140/921 [56] References Cited UNITED STATES PATENTS 3,490,713 1/1970 Nystrom 242/82 R25,477 11/1963 Crum 242/174 3,147,934 9/1964 Godderidge 242/82 2,714,797 8/1955 Drummond et al 242/47.13 X

[5 7] ABSTRACT ciated compression spring. The pins provide the necessary force between the strand material and the engagement surface of the coiler so that the coiler functions satisfactorily and problems of adjustment and wear experienced with priorly used devices are significantly reduced.

12 Claims, 2 Drawing Figures METHODS OF AND APPARATUS FOR COILING STRAND MATERIAL BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to methods of and apparatus for producing compressive forces between a strand material and a drum-type capstan which is being used to advance and coil the strand material.

2. Description of the Prior Art Drum-type capstan and coiler arrangements have been used in the past extensively. Various devices have been used to provide compressive force between the strand material which is being advanced and coiled and a strand-engagement surface of the capstan. These devices have included, for example, rollers which are biased inwardly in pivotally-mounted arms to the strandengagement surface of the capstan and which engage with the strand material to provide force thereon, leaf springs mounted at various points around the periphery of the capstan, and belts of flexible material which are mounted on pulleys separate from the capstan in such a way that the belts are forced to engage with some degree of force on a portion of the strand-engagement surface while traveling around their respective supporting pulleys. In one prior art device, the leaf springs mounted at various points around the periphery of the capstan have been replaced by spring-biased plates.

The prior artdevices used for generating compressive forces as needed on drum-type capstans have the disadvantages of requiring rather precise and timeconsuming adjustments in order that the right degree of force is obtained; and additionally, they are subject to rapid wear particularly when used in the advancing and coiling of metallic wire at high speeds. Stationary springs aresubject to having grooves worn into their surfaces by the passage of wire thereover. Pressure rollers and belts, if they are formed of substantially, nondeformable material, must be adjusted very accurately and if they are formed of resilient materials, such as rubber or other elastomers, are subject to rapid wear due to wire abrading their surfaces.

Leaf springs and rollers also have the disadvantage of being available for entanglement with the strand material in the event of a break occurring in the strand material. When advancing and coiling strand material, a break in the strand which results in the strand becoming entangled with-either leaf springs or rollers may very well result in a bending out of shape or breakage of the leaf springs or rollers.

In still another prior art device, as described in U. S. Pat. No. 3,490,713 issued on Jan. 20, 1970 in the name of Axel C. Nystrom, a strand coiler is provided with a SUMMARY OF THE INVENTION It is an object of the invention to provide new and improved methods of and apparatus for producing compressive forces between a strand material and a drumtype capstan which is being used to advance the strand material.

It is another object of the invention to provide methods of and apparatus for generating compressive forces between a strand of material and a drum-type capstan, wherein a need for periodic adjustment of forceproduction elements is substantially eliminated.

It is a further object of the invention to provide methods of and apparatus for generating compressive forces between strand material and a drum-type capstan, wherein localized wear on force-producing elements is greatly reduced.

It is a still further object of the invention to provide methods of and apparatus for generating and maintaining compressive forces between strand material and a strand-engagement surface of a coiler wherein the probability for strand entanglement and resultant breakage of equipment is greatly reduced.

A method for advancing strand material embodying certain features of the invention may include the steps of wrapping successive sections of strand material on a strand-engagement surface while simultaneously removing similar amounts of preceding successive sections of the strand material from the strandengagement surface and providing and maintaining pressure simultaneously on spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strand-engagement surface to urge successive sections of the strand material against the strand-engagement surface, the forces creating the pressure on the successive sections of strand material at each of the spaced areas of application being applied over a surface, each of the surfaces of applied forces being capable of being rotated about an axis extending transversely of the strand-engagement surface.

A method of advancing strand materials embodying certain features of the invention may also include the steps of wrapping successive sections of strand material on a strand-engagement surface while simultaneously removing similar amounts of preceding successive sections of the strand material from the strandengage ment surface, and providing and maintaining pressure simultaneously on spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strand-engagement surface to urge successive sections of the strand material against the strand-engagement surface, the forces creating the pressure on the successive sections of strand material at each of the spaced areas of application being directed axially toward the strand-engagement surface along lines extending transversely of the strandengagement surface.

An apparatus for advancing strand material embodying certain features of the invention may include a strand-engagement surface, means for wrapping successive sections of the strand material on the strandengagement surface to cause similar preceding successive sections of the strand material to be removed from the strand-engagement surface and spaced means mounted rotatably about axes extendingtransversely of the strand-engagement surface for producing and maintaining pressure simultaneously on spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strandengagement surface to urge the successive sections of the strand material against the strand-engagement surface.

An apparatus for advancing strand material embodying certain features of the invention may also include a strand-engagement surface, means for wrapping successive sections of the strand material on the strandengagement surface to cause similar amounts of preceding successive sections of the strand material to be removed from the strand-engagement surface, and spaced means mounted for axial movement toward the strand-engagement surface along axes extending transversely of the strand-engagement surface for producing and maintaining pressure simultaneously on spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strand-engagement surface to urge successive sections of the strand material against the strand-engagement surface.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and features of the present invention will be more readily understood from the following detailed description of specific embodiments thereof whenread in conjunction with the accompanying drawings, in which: Y i

FIG. 1 is a perspective view of a strand-advancing and coiling apparatus with portions thereof broken away for purposes of clarity and with a departure position of the strand material displaced counterclockwise from its actual position for purposes of clarity.

FIG. 2 is an enlarged fragmentary sectional view of FIG. 1 taken along the line 22 which illustrates the relationship of an inventive, force-producing device and a drum-type capstan, with the size and the position of the strand material being exaggerated for purposes of clarity, and with portions of a strand-engagement surface and a top plate left unsectioned for purposes of clarity.

DETAILED DESCRIPTION Referring now to FIGS. 1 and 2, a strand material is led into a coiling apparatus, designated generally by the numeral 11, from some prior operation (not shown) such as wire drawing. The strand material 10 is passed over a lead-in sheave 12 and is led into a central aperture 13 of a shaft 14. A belt pulley 16 is mounted on the shaft 14, and the pulley is driven by a belt 17 from a power source (not shown).

The shaft 14 is connected to a rotatable plate, designated generally by the numeral 18. A sheave, designated generally by the numeral 19, is mounted rotatably on the rotatable plate 18 by a bracket 21 and projects through an aperture 22 in the shaft 14. The

sheave 19 is provided with a wire-guiding groove 23. The center of the groove 23 is aligned with the center of the aperture 13 so that the strand material 10 which is passing through the aperture can properly engage the sheave '19. y

The strand material 10 progresses from the sheave l9 to a canted, rotatable sheave 24, which is mounted on the rotatable plate 18 by a bracket 26. A bight 27 formed of successive sections of the strand material 10 extends from a groove 28 of the sheave 24 and orbits the strand-engagement surface (see FIG. 1).

An apparatus incorporating the above-identified features is available as a conventional coiler from the Synchro Machine Company, Perth Amboy, N. J., under the trade name Continucoil.

In order to urge the successive sections of the strand material 10 against the strand-engagement surface 29 of the drum-type capstan 31 which is used to advance and coil the strand material, pressure is provided and maintained simultaneously on spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strand-engagement surface. A force-producing device, designated generally by the numeral 36, for creating the pressure on the spaced areas of application completely circumscribes the strand-engagement'surface 29 and includes a plurality of plungers or pins 3737 (see FIG. 2) which are spaced around the capstan 31.

Each of the pins 3737 is preferably circular in cross-section and is made from a hard, wear-resistant material such as tungsten carbide. Also, the end of each of the pins 37-37 which engages the strand material 10 has a beveled end 38 having a surface over which forces are applied and which is dimensioned to apply forces to an area of application that extends over a predetermined number of the convolutions 3232 of the strand material It has been found that properly functioning pins 37-37 for advancing annealed copper wire in size ranges of 19 AWG to 26 AWG, in the case of the capstan 31 being 19 to 32 inches in diameter, can be made approximately 1 inch in length with a diameter of approximately 0.250 inch and with a 30 chamfered edge at one end thereof which engages ones of the convolutions 3232. Moreover, the chamfer is formed so that the one end which engages one of the convolutions 32-32 has a diameter of one-sixteenth to one-eighth inch depending upon the wire size with which the pins are used. In one application, thirty-six of the pins 3737 are spaced uniformly about the capstan 31.

The pins 3737 are mounted in an annular support ring 39 (see FIG. 2) which is supported on a stationary plate 41. The annular support ring 39 is preferably a metal ring having a general shape complementary to the contiguous outer surface of the capstan 31, but the ring should not retard the wrapping of the successive convolutions 32-32 of the strand material 10 about the strand-engagement surface 29 nor impede the release of the convolutions therefrom.

The pins 3737 are mounted reciprocally individually in associated ones of a plurality of bores 4242 formed in the ring 39. Each of the bores 4242 is formed so that the longitudinal axis of the associated one of the pins 37-37 received therein is oriented generally perpendicularly of the strand-engagement surface 29 of the capstan 31 (see FIG. 2). Additionally,

each of the pins 37-37 is urged toward the strandengagement surface 29 into engagement with ones of the convolutions 32-32 by a compression spring 43 which is mounted in the associated bore 42 between the inner end of the pin and the blind end of the bore. The forces imparted by the pins 37-37 to the strand convolutions 32-32 can be pre-set to a predetermined magnitude by a proper selection of the springs 43-43.

In the embodiment shown in FIG. 2, the pins 37-37 are mounted within associated ones of the bores 42-42 sothat the pins are capable of being rotated about the longitudinal axes thereof which are normal to the strand-engagement surface 29. The forces imparted by the springs 43-43 to the associated ones of the pins 37-37 are applied to the surfaces at the beveled ends 38-38 of the pins, the surfaces being capable of being rotated about axes normal to the longitudinal axes of the strand-material being moved along the strandengagement surface 29.

Finally, the annular support ring 39 is fabricated to have a hole 44 (see FIG. 2) connecting each of the bores 42-42 with a top surface of the ring. The holes 4444 function to bleed air or lubricant from the bores 42-42 to prevent unintended pressures from building up within the bores and altering the forces which the pins 37-37 are designed to apply to the convolutions 32-32.

As successive sections of the strand material 10 are removed from the capstan 31, the successive sections are received on a stem 46 ofa takeup device. A plurality of rods 47-47 extend downwardly from the drumtype capstan 31 and cooperate with levers 48-48 which swing inwardly into engagement with the rods to form an accumulator system when one of the stems 46-46 is changed. 7

The rotatable reciprocal mounting of the pins 37-37 along axes extending transversely of the strandengagement surface 29, together with the peripheral disposition of the pins about the strand-engagement surface are extremely valuable in the operation of the coiling apparatus 11. As the longitudinal axes of the convolutions 32-32 are moved downwardly along the strand-engagement surface 29 and perpendicularly of the pins 37-37, the convolutions urge the pins to rotate about the longitudinal axes thereof. The rotation of the pins 37-37 about the longitudinal axes thereof is of assistance in throwing the lower-most convolutions 32-32 of the strand material 10 off the-strandengagement surface 29 and onto a takeup device (not shown) with highly desirable predictability and uniformity.

Since the rotatable mounting of each of the pins 37-37 permits the pins to rotate within the associated ones of the bores 42-42 during the coiling operation, wear across the ends surfaces thereof, which engage successive sections of the strand material 10, is equalized and the grooving of the end surfaces is reduced. Also, the spaced disposition of the pins 37-37 about the circumference of the capstan 31 and directed radially inwardly toward the strand-engagement surface permits the wrapping of the strand material 10 on the strand-engagement surface with much less tension than was possible with some of the prior art devices.

Although an embodiment of the invention has been described hwerein the pins 37-37 of the forceproducing device 36 are mounted rotatably within the ring 39, the strand material 10 could be advanced and coiled in an apparatus in which the pins are not mounted rotatably. In such an embodiment, the pins 37-37 would be mounted for reciprocal movement along axes extending transversely of the strandengagement surface 29 and would be urged inwardly axially toward the strand-engagement surface by associated ones of the springs 43-43.

Also, although an embodiment of the invention has been described wherein the capstan 31 is of the commonly known dead-block type, it is obvious that the invention is capable of being utilized in an advancing and coiling system which incorporates a live-block capstan. Live-block systems are ones in which a capstan component rotates rather than remaining stationary as in the case of dead-block systems. The inven tive force-producing device 36 could be made to function properly with a live-block capstan as well as on a drum-type capstan 31. In that event, the forceproducing device 36 would be mounted so that it would move with the live-block.

It is to be understood that the above-described arrangements are simply illustrative of the invention. Other arrangements may be devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is:

l. A method of advancing strand material, which comprises the steps of:

wrapping successive sections of strand material on a strand-engagement surface while simultaneously removing similar amounts of preceding successive sections of the strand material from the strandengagement surface;

applying forces over each ofa plurality of spaced surfaces to provide and maintain pressure simultaneously on associated spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strand-engagement surface to urge successive sections of the strand material against the strand-engagement surface; and

providing each of the surfaces with the capability of being rotated about an axis extending transversely of the strand-engagement surface.

2. The method of claim 1, wherein the forces creating the pressure on the successive sections of strand material are applied normal to the strand-engagement surface at each of the areas of application.

3. The method of claim I, wherein the axis of rotation of each of the surfaces of applied forces is normal to the longitudinal axes of the strand material at the area of application of the forces.

4. A method of advancing strand materials, which comprises the steps of:

causing relative movement of a strand material and a strand-engagement surface to wrap successive sections of the strand material on the strandengagement surface and simultaneously remove preceding successive sections of the strand material from the strand-engagement surface;

applying forces over each of a plurality of spaced surfaces to provide and maintain pressure simultaneously on associated spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strand-engagement surface to urge successive sections of the strand material against the strand-engagement surface; and

providing a rotatable mounting for the spaced surfaces to allow the spaced surfaces to be rotated about axes extending transversely of the strandengagement surface.

5. A method of advancing strand materials, which comprises the steps of:

wrapping successive sections of strand material on a strand-engagement surface by creating orbital motion in a bight of strand material formed of successive sections thereof around the engagement surface while simultaneously removing similar amounts of preceding successive sections of the strand material from the strandengagement surface;

applying forces normal to the strand-engagement surface and over a plurality of spaced surfaces to provide and maintain pressure simultaneously on the Spaced areas to urge successive sections of the strand material against the strand-engagement surface; and mounting the spaced surfaces for rotation about axes normal to the longitudinal axes of the strand material of associated spaced areas of application on the outer periphery of successive sections of the strand material;

the wrapping of the successive sections of the strand material causing the longitudinal axes of the successive sections of the strand material wrapped on the strand-engagement surface to be moved along the strand-engagement surface and normal to the forces; 7 V

the rotation of the surfaces being a result of the movement of the longitudinal axes of the strand material along the strand-engagement surface normal to the forces.

6. An apparatus for advancing strand material, which comprises:

a strand-engagement surface;

means for wrapping successive sections of strand material on the strand-engagement surface to cause similar amounts of preceding successive sections of the strand material to be removed from the strandengagement surface; spaced means for producing and maintaining pressure simultaneously on spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strand-engagement surface to urge successive sections of the strand material against the strand-engagement surface; and means for mounting rotatably the spaced means about axes extending transversely of the strandengagement surface.

7. The apparatus of claim 6, wherein the axes of rotation of the spaced means are normal to the longitudinal axes of the strand material at the areas of application of the forces.

8. The apparatus of claim 6, wherein the axes along which the spaced means for creating pressure on the spaced areas of application are mounted are normal to the strand-engagement surface to direct forces normal strand a plurality of pins spaced about the strandengagement surface, each of the pins mounted forrotation about and reciprocally along an axis thereof extending normally of the strandengagement surface; and

means for urging each of the pins axially toward the strand-engagement surface 10. An apparatus for advancing strand material, which includes:

a strand-engagement surface; means for wrapping successive sections of the strand material on the strand-engagement surface to cause similar amounts of preceding successive sections of the strand material to be removed from the strand-engagement surface;

plurality of pins spaced about the strandengagement surface for producing and maintaining pressure simultaneously on spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strandengagement surface; means mounting the pins for reciprocal movement along axes extending normally of the strandengagement surface to direct forces which cause the pressure on the spaced areas along the axes; and means for urging each of the pins axially toward the strand-engagement surface to produce and maintain pressure simultaneously on the spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strand-engagement surface to urge successive sections of the strand material against the strandengagement surface. 11. An apparatus for advancing strand material, which comprises:

a strand-engagement surface; means causing relative movement of the strand material and the strand-engagement surface for wrapping successive sections of strand material on the strand-engagement surface and simultaneously removing similar amounts of preceding successive sections of the strand material from the strandengagement surface;

spaced means for producing and maintaining pressure simultaneously on spaced areas of application on the outer periphery of successive sections of the strand material wrapped on'the strand-engagement surface to urge successive sections of the strand material against the strand-engagement surface; and means for mounting rotatably the spaced means about axes extending transversely of the strandengagement surface; 7 the rotation of the spaced means being a result of the movement of the longitudinal axes of successive sections of the strand material along the strandengagement surface transversely of the spaced means. 12. An apparatus for advancing strand material, which comprises:

a strand-engagement surface;

means creating orbital motion in a bight of strand material against the strand-engagement surface;

and

means mounting the spaced means for rotation about and for axial movement toward the strandengagement surface along axes extending transversely of the strand-engagement surface. 

1. A method of advancing strand material, which comprises the steps of: wrapping successive sections of strand material on a strandengagement surface while simultaneously removing similar amounts of preceding successive sections of the strand material from the strand-engagement surface; applying forces over each of a plurality of spaced surfaces to provide and maintain pressure simultaneously on associated spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strand-engagement surface to urge successive sections of the strand material against the strand-engagement surface; and providing each of the surfaces with the capability of being rotated about an axis extending trAnsversely of the strandengagement surface.
 2. The method of claim 1, wherein the forces creating the pressure on the successive sections of strand material are applied normal to the strand-engagement surface at each of the areas of application.
 3. The method of claim 1, wherein the axis of rotation of each of the surfaces of applied forces is normal to the longitudinal axes of the strand material at the area of application of the forces.
 4. A method of advancing strand materials, which comprises the steps of: causing relative movement of a strand material and a strand-engagement surface to wrap successive sections of the strand material on the strand-engagement surface and simultaneously remove preceding successive sections of the strand material from the strand-engagement surface; applying forces over each of a plurality of spaced surfaces to provide and maintain pressure simultaneously on associated spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strand-engagement surface to urge successive sections of the strand material against the strand-engagement surface; and providing a rotatable mounting for the spaced surfaces to allow the spaced surfaces to be rotated about axes extending transversely of the strand-engagement surface.
 5. A method of advancing strand materials, which comprises the steps of: wrapping successive sections of strand material on a strand-engagement surface by creating orbital motion in a bight of strand material formed of successive sections thereof around the strand-engagement surface while simultaneously removing similar amounts of preceding successive sections of the strand material from the strand-engagement surface; applying forces normal to the strand-engagement surface and over a plurality of spaced surfaces to provide and maintain pressure simultaneously on the spaced areas to urge successive sections of the strand material against the strand-engagement surface; and mounting the spaced surfaces for rotation about axes normal to the longitudinal axes of the strand material of associated spaced areas of application on the outer periphery of successive sections of the strand material; the wrapping of the successive sections of the strand material causing the longitudinal axes of the successive sections of the strand material wrapped on the strand-engagement surface to be moved along the strand-engagement surface and normal to the forces; the rotation of the surfaces being a result of the movement of the longitudinal axes of the strand material along the strand-engagement surface normal to the forces.
 6. An apparatus for advancing strand material, which comprises: a strand-engagement surface; means for wrapping successive sections of strand material on the strand-engagement surface to cause similar amounts of preceding successive sections of the strand material to be removed from the strand-engagement surface; spaced means for producing and maintaining pressure simultaneously on spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strand-engagement surface to urge successive sections of the strand material against the strand-engagement surface; and means for mounting rotatably the spaced means about axes extending transversely of the strand-engagement surface.
 7. The apparatus of claim 6, wherein the axes of rotation of the spaced means are normal to the longitudinal axes of the strand material at the areas of application of the forces.
 8. The apparatus of claim 6, wherein the axes along which the spaced means for creating pressure on the spaced areas of application are mounted are normal to the strand-engagement surface to direct forces normal of the strand-engagement surface.
 9. The apparatus of claim 6, wherein the spaced means includes: a plurality of pins spaced about the strand-engagement surface, each of The pins mounted for rotation about and reciprocally along an axis thereof extending normally of the strand-engagement surface; and means for urging each of the pins axially toward the strand-engagement surface.
 10. An apparatus for advancing strand material, which includes: a strand-engagement surface; means for wrapping successive sections of the strand material on the strand-engagement surface to cause similar amounts of preceding successive sections of the strand material to be removed from the strand-engagement surface; a plurality of pins spaced about the strand-engagement surface for producing and maintaining pressure simultaneously on spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strand-engagement surface; means mounting the pins for reciprocal movement along axes extending normally of the strand-engagement surface to direct forces which cause the pressure on the spaced areas along the axes; and means for urging each of the pins axially toward the strand-engagement surface to produce and maintain pressure simultaneously on the spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strand-engagement surface to urge successive sections of the strand material against the strand-engagement surface.
 11. An apparatus for advancing strand material, which comprises: a strand-engagement surface; means causing relative movement of the strand material and the strand-engagement surface for wrapping successive sections of strand material on the strand-engagement surface and simultaneously removing similar amounts of preceding successive sections of the strand material from the strand-engagement surface; spaced means for producing and maintaining pressure simultaneously on spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strand-engagement surface to urge successive sections of the strand material against the strand-engagement surface; and means for mounting rotatably the spaced means about axes extending transversely of the strand-engagement surface; the rotation of the spaced means being a result of the movement of the longitudinal axes of successive sections of the strand material along the strand-engagement surface transversely of the spaced means.
 12. An apparatus for advancing strand material, which comprises: a strand-engagement surface; means creating orbital motion in a bight of strand material formed of successive sections thereof around the strand-engagement surface for wrapping successive sections of strand material on the strand-engagement surface to cause similar amounts of preceding successive sections of the strand material to be removed from the strand-engagement surface; spaced means for producing and maintaining pressure simultaneously on spaced areas of application on the outer periphery of successive sections of the strand material wrapped on the strand-engagement surface to urge successive sections of the strand material against the strand-engagement surface; and means mounting the spaced means for rotation about and for axial movement toward the strand-engagement surface along axes extending transversely of the strand-engagement surface. 